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US3021B
5 BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS TRIPPLE LDO CONTROLLER
PRELIMINARY DATASHEET
FEATURES
Provides Single Chip Solution for Vcore, GTL+ ,AGP Bus, and 1.8V Automatic Voltage Selection for AGP slot Vddq supply Linear regulator controller on board for 1.8V Designed to meet Intel Latest VRM specification for next generation micrprocessors On board DAC programs the output voltage from 1.3V to 3.5V Linear regulator controller on board for 1.5V GTL+ supply Loss less Short Circuit Protection for all outputs Synchronous operation allows maximum efficiency Patented architecture allows fixed frequency operation as well as 100% duty cycle during dynamic load Minimum part count Soft Start High current totem pole driver for direct driving of the external Power MOSFET Power Good function Monitors all Outputs OVP Circuitry Protects the Switcher Output and generates a Fault output
DESCRIPTION
The US3021B controller IC is specifically designed to meet Intel specification for next generation microprocessor applications requiring multiple on board regulators . The US3021B provides a single chip controller IC for the Vcore , 3LDO controllers, one with the automatic select pin that connects to the TYPE DETECT pin of the AGP slot for the AGP Vddq supply, one for GTL+ and the other for the 1.8V chip set regulator as required for the next generation PC applications. The US3021B typically uses Bipolar transistors for Vout3(1.5V) and Vout4(1.8V) however if Vaux pin is connected to 12V, then MOSFETs can also be used as external pass elements. No external resistor divider is necessary for any of the regulators. The switching regulator feature a patented topology that in combination with a few external components as shown in the typical application circuit ,will provide well in excess of 20A of output current for an on- board DC/DC converter while automatically providing the right output voltage via the 5 bit internal DAC .The US3021B also features, loss less current sensing for both switcher by using the Rds-on of the high side Power MOSFET as the sensing resistor, an output under voltage shutdown that detects short circuit condition for the linear outputs and latches the system off, and a Power Good window comparator that switches its open collector output low when any one of the outputs is outside of a pre programmed window.
APPLICATIONS
Total Power Soloution for Next Generation Intel Processor application
TYPICAL APPLICATION
5V 3.3V LINEAR CONTROL SWITCHER CONTROL
Vout1
Vout2
US3021B
LINEAR CONTROL Vout3
LINEAR CONTROL Vout4
3021Bapp3-1.1
PACKAGE ORDER INFORMATION
Ta (C) 0 TO 70
Rev. 1.4 12/8/00
Device US3021BCW
Package 28 pin Plastic SOIC WB
4-1
US3021B
ABSOLUTE MAXIMUM RATINGS
V5 supply Voltage ........................................... 7V V12 Supply Voltage ............................................ 20V Storage Temperature Range ................................. -65 TO 150C Operating Junction Temperature Range .......... 0 TO 125C
PACKAGE INFORMATION
28 PIN WIDE BODY PLASTIC SOIC (W)
TOP VIEW
Drive2 1 Fix 2 VID4 3 VID3 4 VID2 5 VID1 6 VID0 7 PGood 8 SD 9 Vsen2 10 Select 11 SS 12 Fault / Rt 13 Vsen4 14
28 V12 27 UGate 26 Phase 25 LGate 24 PGnd 23 OCSet 22 Vsen1 21 Fb 20 V5 19 Vsen3 18 Drive3 17 Gnd 16 Vaux 15 Drive4
JA =80C/W
ELECTRICAL SPECIFICATIONS
Unless otherwise specified ,these specifications apply over ,V12 = 12V, V5 = 5V and Ta=0 to 70C. Typical values refer to Ta =25C. Low duty cycle pulse testing are used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS Supply UVLO Section UVLO Threshold-12V Supply ramping up 10 V UVLO Hysterises-12V 0.6 V UVLO Threshold-5V Supply ramping up 4.4 V UVLO Hysterises-5V 0.3 V Supply Current Operating Supply Current V12 6 mA V5 30 Switching Controllers; Vcore (Vsen 1) and AGP (Vsen 2) VID Section (Vcore only) DAC output voltage (note 1) 0.99Vs Vs 1.01Vs V DAC Output Line Regulation 0.1 % DAC Output Temp Variation 0.5 % VID Input LO 0.8 V VID Input HI 2 V VID input internal pull-up resistor to V5 27 k Vsen2 Voltage Select<0.8V 1.5 V Select>2V 3.3 V
4-2
Rev. 1.4 12/8/00
US3021B
Error Comparator Section Input bias current Input Offset Voltage Delay to Output Current Limit Section C.S Threshold Set Current C.S Comp Offset Voltage Hiccup Duty Cycle Output Drivers Section Rise Time Fall Time Dead band Time Between High side and Synch Drive (Vcore Switcher Only) Oscillator Section (internal) Osc Frequency 1.8V Regulator (Vsen 4) Vsense Voltage Vo4 Vsense Voltage Input bias current Output Drive Current 1.5V Regulator (Vsen 3) Vsense Voltage Vsense Voltage Input bias current Output Drive Current Power Good Section Vsen1 UV lower trip point Vsen1 UV upper trip point Vsen1 UV Hysterises Vsen1 HV upper trip point Vsen1 HV lower trip point Vsen1 HV Hysterises Vsen2 trip point Vsen4 trip point Vsen3 trip point Power Good Output LO Power Good Output HI Fault (Overvoltage) Section Core O.V. upper trip point Core O.V. lower trip point FAULT Output HI Soft Start Section Soft Start Current 2 +2 100 200 -5 Css=0.1 uF CL=3000pF CL=3000pF 10 70 70 +5 uA mV nS uA mV % nS nS
-2 Vdiff=10mV
CL=3000pF Rt=Open Ta=25, Drive4 = Vsen4
200 217 1.800 1.800 2 50
nS Khz V V uA mA
Vaux-Vdrive>0.6V
Vo3
Ta=25, Drive3 = Vsen3
1.500 1.500 2 50
Vaux-Vdrive>0.6V
V V uA mA
Vsen1 ramping down Vsen1 ramping up Vsen1 ramping up Vsen1 ramping down Select<0.8V Select>2V Fix=GND Fix=Open Fix=GND Fix=Open RL=3mA RL=5K pull up to 5V Vsen1 ramping up Vsen1 ramping down Io=3mA OCset=0V , Phase=5V
0.90Vs 0.92Vs .02Vs 1.10Vs 1.08Vs .02Vs 1.100 2.560 0.920 1.320 0.920 1.140 0.4 4.8 1.17Vs 1.15Vs 10 20
V V V V V V V V V V V V V V V V V uA
Rev. 1.4 12/8/00
4-3
US3021B
Note 1: Vs refers to the set point voltage given in Table 1. D4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 D3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 D2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 D1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 D0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Vs 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 1.85 1.90 1.95 2.00 2.05 D4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 D2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 D1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 D0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Vs 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5
Table 1 - Set point voltage vs. VID codes
PIN DESCRIPTIONS
PIN# PIN SYMBOL 7 VID0 Pin Description LSB input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic "1" as either HI or Open. When left open,his pin is pulled up internally by a 27k resistor to 5V supply. Input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic "1" as either HI or Open. When left open,his pin is pulled up internally by a 27k resistor to 5V supply. Input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic "1" as either HI or Open. When left open,his pin is pulled up internally by a 27k resistor to 5V supply. MSB input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic "1" as either HI or Open. When left open,his pin is pulled up internally by a 27k resistor to 5V supply. This pin selects a range of output voltages for the DAC.When in the LOW state the range is 1.3V to 2.05V and when it switches to HI state the range is 2.0V to 3.5V. This pin is TTL compatible that realizes a logic "1" as either HI or Open. When left open,his pin is pulled up internally by a 27k resistor to 5V supply. This pin is an open collector output that switches LO when any of the outputs are outside of the specified under voltage trip point. It also switches low when Vsen1 pin is more than 10% above the DAC voltage setting. This pin provides the feedback for the synchronous switching regulator. Typically this pin can be connected directly to the output of the switching regulator. However, a resistor divider is recommended to be connected from this pin to vout1 and GND to adjust the output voltage for any drop in the output voltage that is caused by the trace resistance. The value of the resistor connected from Vout1 to FB1 must be less than 1000. This pin controls the gate of an external MOSFET for the AGP linear regulator. This pin provides shutdown for all the regulatos. A TTL compatible, logic level high applied to this pin disables all the outputs and discharges the soft start capacitor. The SD signal turns off the synchronous allowing body diode to conduct and discharge the output cap.
6
VID1
5
VID2
4
VID3
3
VID4
8
PGOOD
21
FB
1 9
Drive2 SD
4-4
Rev. 1.4 12/8/00
US3021B
PIN# PIN SYMBOL 22 Vsen1 10 Vsen2 Pin Description This pin is internally connected to the undervoltage and overvoltage comparators sensing the Vcore status. It must be connected directly to the Vcore supply. This pin provides the feedback for the AGP linear regulator. The Select pin when connected to the "Type Detect" pin of the AGP slot automatically selects the right voltage for the AGP Vddq. This pin controls the gate of an external MOSFET for the 1.8V chip set linear regulator. This pin is connected to the Drain of the power MOSFET of the Core supply and it provides the positive sensing for the internal current sensing circuitry. An external resistor programs the C.S threshold depending on the Rds of the power MOSFET. An external capacitor is placed in parallel with the programming resistor to provide high frequency noise filtering. This pin is connected to the Source of the power MOSFET for the Core supply and it provides the negative sensing for the internal current sensing circuitry. This pin provides the soft start for all the regulators. An internal current source charges an external capacitor that is connected from this pin to GND which ramps up the outputs of the regulators, preventing the outputs from overshooting as well as limiting the input current. The second function of the Soft Start cap is to provide long off time (HICCUP) for the synchronous MOSFET during current limiting. This pin has dual function. It acts as an output of the OVP circuitry or it can be used to program the frequency using an external resistor . When used as a fault detector, if any of the switcher outputs exceed the OVP trip point, the FAULT pin switches to 12V and the soft start cap is discharged. If the FAULT pin is to be connected to any external circuitry, it needs to be buffered. This pin controls the gate of an external transistor for the 1.5V GTL+ linear regulator. This pin provides the feedback for the linear regulator that its output drive is Drive3. This pin is normally connected to 3.3V or 5V input. When connected to the 12V supply, it provides gate drive voltage for the # 3 and #4 (Drive 3 and 4) linear regulator's pass transistors in case MOSFET transistors are being used instead of Bipolars. This pin provides the feedback for the linear regulator that its output drive is Drive4. This pin serves as the ground pin and must be connected directly to the ground plane. This pin serves as the Power ground pin and must be connected directly to the GND plane close to the source of the synchronous MOSFET. A high frequency capacitor (typically 1 uF) must be connected from V12 pin to this pin for noise free operation. Output driver for the synchronous power MOSFET for the Core supply. Output driver for the high side power MOSFET for the Core supply. This pin is connected to the 12 V supply and serves as the power Vcc pin for the output drivers. A high frequency capacitor (typically 1 uF) must be placed close to this pin and PGND pin and be connected directly from this pin to the GND plane for the noise free operation. 5V supply voltage. A high frequency capacitor (0.1 to 1 uF) must be placed close to this pin and connected from this pin to the GND plane for noise free operation. This pin provides automatic voltage selection for the AGP switching regulator. When it is pulled LO, the voltage is 1.5V and when left open or pulled to HI, the voltage is 3.3V. Leaving this pin open provides fixed output voltages of the 1.5V and 1.8V for the #3 and #4 linear regulators. When this pin is grounded the reference to the linear regulators are set to 1.26V and therefore the output of the regulators can be programmed to any voltages above the 1.26V using; Vout=1.26*(1+Rtop/Rbot) Where: Rtop=Top resistor connected from the output to the Vsense pin Rbot=Bottom resistor connected from the Vsense pin to ground.
15 23
Drive4 OCSET
26 12
PHASE SS
13
FAULT/Rt
18 19 16
Drive3 Vsen3 Vaux
14 17 24
Vsen4 GND PGND
25 27 28
LGATE UGATE V12
20 11 2
V5 Select FIX
Rev. 1.4 12/8/00
4-5
US3021B
BLOCK DIAGRAM
V12 V5 SD Vsen1 PGood Vsen3 Vsen4
Enable
Fb
1.17Vset Over Voltage Vset Enable V12
UVLO
UGate PWM Control
V12
+
1.1Vset
Slope Comp
LGate Osc Phase
Over Current
Fix
0.9Vset
Enable
Vaux Drive4
R 1.26V 3R
Soft Start & Fault Logic
OCSet 200uA PGnd Gnd Fault / Rt SS
Vset
Drive3 Select
R 3R 1.5V 3.3V
VID0 VID1 5Bit DAC VID2 VID3 VID4
Drive2 Vsen2
3021Bblk1-1.4
Figure 1 - Simplified block diagram of the US3021.
4-6
Rev. 1.4 12/8/00
US3021B
TYPICAL APPLICATION
(Dual Layout with HIP6021)
R1 12V
L1 5V C1 C2 28 V12 9 SD 2 FIX Type Detect 11 SELECT PHASE 26 R7 LGATE 25 R15 R5 3.3Vin C6 Q2 1 DRIVE2 16 Vaux PGND 24 VSEN1 22 FB 21 R9 Vout2 1.5V / 3.3V C13 10 VSEN2 C16 R8 C14 R3 R14 C7 Q3 C22 R6 R10 23 OCSET UGATE 27 R4 C5 R2 C4 C3
Q1 L2 Vcore
U1
V5 20 (COMP) C15 VID0 7
C17
R12
R11
Q4
18 DRIVE3
VID1 6 VID2 5
Vout3 1.5V C18
19 VSEN3
VID3 4 VID4 3 Vcc3 R13 PGOOD 8 PGood C21
Q5
15 DRIVE4
FAULT/RT 13 SS 12 C20
VSEN4 GND 14 17 Vout4 1.8V C19
3021Bapp2-1.0
Figure 2 - Typical application of US3021B in a dual layout with HIP6021 for an on board DC-DC converter providing power for the Vcore , GTL+, 1.8V chip set supply as well as auto select AGP supply for the next generation PC applications.
Part# HIP6021 US3021B S - Short
R3 O O
R5 S O
R9 O O
R10 V O
R15 O S
C15 O V
C16 V O
C17 V O
O - Open
V - See Unisem or Harris parts list for the value.
Table 2 - Dual layout component table
Note 1: If Q4 and Q5 are changed to MOSFETs such as IRLR024, then R2 is short and R4 is open.
Rev. 1.4 12/8/00
4-7
US3021B
US3021M Application Parts List Dual Layout with HIP6021 Ref Desig Q1 Q2 Q3 Q4,5 L1 L2 C1 C2,3 C4 C5 C6,18 C7 C13,19 C14,15 C16,17 C20,21 C22 R1 R2 R3,5,12 R4,7,14 R6,8,10 R9 R11 R13 R15 Description MOSFET MOSFET MOSFET with Schottky Transistor Inductor Inductor Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Ceramic Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Qty 1 1 1 2 1 1 1 2 1 1 2 6 1 2 2 2 1 1 1 3 3 3 1 1 1 1 Part # IRL3103S, TO263 package IRLR3103, TO252 package IRL3103D1S, TO263 package 2SD1760, TO252 package L=1uH, 5052 core with 4 turns of 1.0mm wire L=2.7uH, 5052B core with 7 turns of 1.2mm wire 10MV470GX, 470uF,10V 10MV1200GX, 1200uF,10V 220pF, 0603 1uF, 0805 6MV1000GX, 1000uF,6.3V 6MV1500GX, 1500uF,6.3V, 6MV1500GX, 1500uF,6.3V, 1uF, 0603 See Table 2, dual layout component 0603 * 2 0.1uF, 0603 1000pF, 0603 10, 5%, 0603 3.3k, 5%, 0603 See Table 2, dual layout component 0603 * 3 4.7, 5%, 1206 2.2k, 1%, 0603 0, 0603 220k, 1%, 0603 10k, 5%, 0603 0, 0603 Manuf IR IR IR ROHM Micro Metal Micro Metal Sanyo Sanyo
Sanyo Sanyo Sanyo
4-8
Rev. 1.4 12/8/00

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